基坑阳角是变形控制的不利位置,在设计中应予以重点加固。在基坑工程领域引入冗余度设计理论的概念,对土钉支护基坑的阳角进行腰梁加固,并对其冗余度进行分析。对比分析了原体系与冗余体系的坑壁水平位移、土钉轴力等内容;研究了局部土钉失效时,土钉-腰梁支护体系的工作状况。结果证明对土钉支护基坑的阳角进行腰梁加固能够有效控制危险位置位移,转移冗余荷载,增加荷载传递路径,即能够提高支护体系冗余度。 The corners of foundation pit are the unfavorable positions of deformation control, and should be emphasized in the design. In the field of foundation pit engineering, the concept of redundancy design theory is introduced to reinforce the lumbar beam on the male angle of the soil nailing support pit and to analyze its redundancy. The horizontal displacement of the pit wall and the axial force of the soil nail were compared and analyzed between the original system and the redundant system. The working conditions of the soil nailing-lumbar support system when the local soil nail failure was studied. The results show that the strengthening of the lumbar beam at the male angle of the soil nailing support pit can effectively control the displacement of the dangerous position, transfer the redundant load and increase the load transfer path, which can improve the redundancy of the support system.